Our principal objectives are to determine the chemical and physical properties of respiratory mucins, to determine how perturbations of particular moieties affect the physical properties, and to determine whether there are differences in these properties between mucins obtained from the airways of healthy individuals and from the airways of patients with chronic obstructive pulmonary diseases, such as bronchial asthma, bronchitis, bronchorrhea and cystic fibrosis. As a result of our recent studies on lung mucosal gel from a patient with bronchial asthma (Rose, Lynn, and Kaufman, Biochem. (1979) 18, 4030) we have developed techniques for the dissolutions of lung mucosal gel and for the resolution of the mucin glycoprotein and protein components. We will apply these techniques to the dissolution and resolution of the components of the mucosal gel obtained from healthy airways and will compare the chromatographic and electrophoresis profiles of mucus from healthy and diseased airways. We will compare the chemical properties of the mucin glycoproteins from healthy airways and their pathological counterparts with regard to amino acid and carbohydrate composition, concentration of sulfate and sialic acid, the types of oligosaccharides obtained in the beta-elimination reaction, the position of the oligosaccharides in the oligosaccharide chains, and the fraction of serine and threonine residues substituted in the oligosaccharide chains. We will also examine the rheological properties of the lung mucin glycoproteins and the effect of chemical modifications of the mucins --proteolysis, carboxymethylation -- on their physical and rheological properties. The proteolysis patterns and products, the localization of the cysteinyl residues that are unreactive in the first carboxymethylation cycle, and the localization of the thiol residues relative to the oligosaccharides will be investigated.